08 Spain D40 4 Hi not engaging but 4Lo engages

[IH8LAWWW]

Hi all im having some issues with my 2008 spain built S40 STX 6spd Manual. My 4 hi is not engaging { cannot hear solenoid and it does not illuminate on the dash} But the little 4x4 light works and solenoid engages fine when it is engaged in 4lo it sometimes makes a crunch noise / grind noise from the front while under load it is not all the time and it sounds like left side but feels like the middle. { replaced brand new CVS less than a week ago so i know its not that} im at a loss atm for what is causing it im trying to eliminate all my little demons as i plan on doing some touring / exploring at the end of the year. Could the front diff be shot and causing my 4wd issues or are the solenoids on the box the issue and its not staying engaged possibly i don't have any flashing lights for abs etc on the dash. Any help would be appreciated.

Thanks Adam.

 

[Old.Tony]

Hi, I'm working on oldest to newest messages and I'm not sure if this has been answered in another thread yet ...

It's strange that you can get to 4LO if 4HI isn't working. The servo that changes the transfer case rotates 270 degrees from its starting position in 2HI, engaging 4HI at the 90 degree mark and then changing the gear ratio in the following 180 degrees.

So 4HI is there, but it's not indicating this to you? Try this: engage 4HI and try doing a u-turn on solid ground (concrete/ashphalt). Things should tighten up and the car should become quite reluctant to move. If this has worked, you're in 4HI but the indicator in the dash may be malfunctioning.

For that, I'd check all the electrical connectors on the transfer case. If that doesn't give you joy, it's possible that you need to replace the sensor on the transfer case. Engaging 4HI is little more than a pair of pawls engaging and pressing on a switch (it's marginally more complicated than that) to bring the front drive shaft into action.

If there's no binding of the transmission in a U-turn, see if you can put it on a hoist so all 4 wheels can turn freely. With the gearbox in neutral and the transfer in 4HI, rotating the REAR drive shaft should cause the front drive shaft to rotate and the wheels should respond.

If you engage 4LO and try a U-turn the vehicle should bind up tight. If it doesn't, you've basically got a 2WD car with high and low range, and it's either a busted front diff or a broken uni. A broken axle or CV joint(s) is also possible.